LWB to SWB questions...

[texascowboy593]

I've read Glocks lwb to swb conversion in faq. My questions are :

My GMC has leaf springs... Anyone found out if it will work with leaf springs (measurements)

What driveshaft will I now need? Part #'s anyone? Running a 3speed manual in it.

I plan on doing this fairly soon. Ive got a welding shop in mind to take it to and want to get all the minor things collected for when its done. The cab and fenders are in great shape but the bed and bed floor are absolutely shot! Figured I'd start from scratch w/ a new or better than current bed...

Any other pointers are more than welcome. Thx to everyone in advance!

[Oldtruckfanatic]

I just did this to my 69. I haven't read the writeup you mentioned on here yet but the type of suspension won't matter at all.The important part is where the frame is cut and how well it's put back together. I'm just having the local driveline and gear shop make me a driveshaft so I won't be any help on what fits it stock. I'm hoping to get a few pics of my shortening job on by this weekend I'll be watching this post to see if I missed anything myself :-)

[roj2323]

i also have a question on the same subject. please forgive me if this is concidered thread high jacking.

will a short bed bolt onto a longbed frame without moving brackets? i.e. a 2ft gap between the bed and cab?

ondrew

[Oldtruckfanatic]

I cut my bed but I put a stepside bed on mine to size it up and it bolted up faily well to the front 6 mounts and I had to drill a pair of holes for the back set because the 8" I lobbed off the frame had the longbed mounting holes in them. I did have to fudge the bed a little bit to get what I wanted for a good cab to bed gap though.

[glock35ipsc]

Originally Posted by roj2323

i also have a question on the same subject. please forgive me if this is concidered thread high jacking.

will a short bed bolt onto a longbed frame without moving brackets? i.e. a 2ft gap between the bed and cab?

ondrew

Yes, only it will be a 1ft gap. When shortening a LWB frame, the most forward pair of brackets are removed. All the ones behind them remain in the same location.

From my FAQ:

Remove the forward-most pair of bed mounts. They are no longer needed. There is one setting on the frame in the lower right of this pic. The left one is already gone.

[49studebaker]

The leaf spring mounts are not an issue. Most everyone makes the cut between the cab mounts. As long as you measure the distance between those you won't have a problem.

[Oldtruckfanatic]

^^^^ Thats exactly where mine is cut. I had to relocate the rear cab mounts. I took 12 inches out of the middle and 8 inches off the back end of the frame. Went back together pretty easily took me longer to line up the frame for welding than the rest of the work did (measure 20 times weld once ) LOL

[glock35ipsc]

Originally Posted by 49studebaker

The leaf spring mounts are not an issue. Most everyone makes the cut between the cab mounts. As long as you measure the distance between those you won't have a problem.

Makes sense now. Like I said, I have never looked at a leaf frame, but looking at that angle I can guess that the cut is WAAAAY in front of the front hanger. I must be having a brain-fart kind of day, cause that is really obvious to me now! No different than a coil frame then; cut, roll forward, weld.

[Oldtruckfanatic]

I copied an article in Classic Trucks magazine to do mine. The article was called "The long and short of it" I still have the issue maybe I can scan the pages. They did a 45 degree slant cut on the truck in the articles but I opted to do mine the same way 49stude did his. My dad taught me to cut frames this way for clips way back it the day. Awesome thread guys! Oops...I found the magazine lol it's the april 2003 issue of custom classic trucks and the name of the article is actually "Longbed, No!- Shortbed, Yes!"

[texascowboy593]

Looks like a big thread's a buildin'... ^^^... Let's get the questions on the "little things" of the conversion out there and see what we all can pool together for answers... This site is the absolute BEST!

[Ackattack]

I've decided to do this too, but I'm just going to buy a short bed junker frame. I want both the short bed and coil springs instead of the leafs taht I have now.

[glock35ipsc]

TexasCowboy -

I still have not had a chance to look over a LWB leaf frame, but here are my thoughts on it.....

Measure forward of the front spring hanger bracket exactly 12". See if it will be possible to mount the bracket to the spot on the frame that is 12" forward of it's current location.

Before removing or cutting anything, measure from a point on the rear spring hanger bracket that mounts to the frame to a point on the front bracket. Note the distance, but more importantly, note the EXACT points you measured from on the brackets. Also pick different points to measure from the bracket to the frame both on the top of the frame rail and the bottom rail, just to be sure you can relocate the bracket in EXCATLY the same position. Save for later.

Now, without looking at a leaf frame, I see no reason why this can't be done. Don't remove the rear spring hanger bracket from the frame, that would not be necessary. In short: Remove the front brackets from the frame (leaving the springs attached if possible, just use caution), cut the frame, roll the rear portion of the frame forward, square it up and weld together. Then using the measurements taken before cutting, locate where the front spring hangers need to be on the frame, drill and attach.

[texascowboy593]

Great info guys! I plan on taking the truck to a welding shop for the service. (Ive never welded before!) All this info and pics will be printed and given to the welding shop so they know exactly what to do... What do you think it will cost approx? BTW Glock, Your faq thread is excellent! Ive been contemplating doing this for quite sometime now... THX

[bubba72]

http://www.earlyclassic.com/tech.asp...20No!-Shortbed

if this works here is an article i saw. i just got a donor 71 chevy disc 5 lug long bed to try this soon


joe

[glock35ipsc]

I HIGHLY recommend not using ECE's method. Any variation of the step method that I used in my FAQ and that 49studebaker and efabman use is prefered. It is simple to align and square and is and much, much stronger. I make my living by melting metal together, and would not use the 45* method ever. Granted, it does shorten the frame and it does provides means to re-attach it, but their are far better ways to do it. And I won't comprimise my safety or anyone elses safety just to make a few less cuts.

OK, I'll climb down off my Hope I didn't offend anyone......

[Oldtruckfanatic]

I only mentioned the article because it shows where to cut and thats how I got the idea to do mine at the end of my post it says I step cut it because I was taught to cut frames that way by my old man when doing clips. It also had measurements which I found helpful. Definitely didn't suggest doing anything dangerous for anyone.

[glock35ipsc]

I hear ya! I didn't think by any means that anyone was suggesting anything dangerous, I just wanted to let the folks know that this I something I feel very strongly about.

But, with regards to the article, we all need to get our ideas from somewhere. Whether it comes to use on the throne (some of my best ideas poped into my head there, hehe), on in a magazine, this site has been the single best source of ideas and information for me. I just want to share what I have learned!

[Oldtruckfanatic]

I agree totally I have seen so many things on thise site I have liked in the three or four days since I joined I could keep busy with the ideas without magazine subscritions for the next ten years. I love this site I'm glad I accidentally ran across it.

[Brad]

Maybe this will help you in some way.

http://67-72chevytrucks.com/vboard/s...d.php?t=181633

[bubba72]

i was just trying to be helpful, but here is my question. if a prof. welder welds the frame and gets good penetration isn't it going to be stronger then the frame itself? i have heard of welds cracking and stuff like that, but... help me with some knowledge cause i was thinking about the ece way because cutting a frame at 45 would be alot easier with a sawzall then the step cut. i was also thinking about fish plating the weld.


thanks joe

[TravisH]

Originally Posted by bubba72

i was just trying to be helpful, but here is my question. if a prof. welder welds the frame and gets good penetration isn't it going to be stronger then the frame itself? i have heard of welds cracking and stuff like that, but... help me with some knowledge cause i was thinking about the ece way because cutting a frame at 45 would be alot easier with a sawzall then the step cut. i was also thinking about fish plating the weld.

In theory the absolute best weld is equally as strong as the metal alongside it, but its near impossible to do in practice. I don't want to go into all the metalurgical properties that would affect and change (and don't consider me an expert on that either) but consider this:

You have a piece of steel that has the same strength all over it. If you bent this piece from the edges it would fold in the middle, keep bending it and it would break there. Now say you get it welded and theres absolutely no defects in the weld but it is stronger (coming from your post). If you bent the piece the exact same way it will bend next to the weld instead of on it (where it bent the previous time). The problem with a stronger weld is that it will bend at the edge of the weld with less force than before because the weld will resist deformation more, thereby making the piece weaker.

By no means take this post as gospel, there are far to many factors to discuss here and I've already confessed that I'm no expert


On my frame I did the step cut with radiused corners like in glocks FAQ. I V-grooved the outer edge and then did a back weld (grind out a slot from behind and reweld that). I still used a 16" piece of C-channel on the inside to reinforce.

[glock35ipsc]

Any welding will actually reduce the strength of the surrounding area that is welded. With the 45* cut, it is the way the frame is stressed under normal use that puts the 45* cut at a bad angle. If you can imagine a crack starting at the bottom of the frame rail, any bump or whoop-de-doo that flexes the frame will make the crack worse, and continue cracking until it reaches the top.

Think of the 45* cut line itself as that 'crack' waiting to happen. Fish plating is absolutely necessary no matter how it is cut. The step cut helps to eliminate any weak spots where stress cracks can start, as well as provide more area of penetration.

If you take your time and move slow and deliberatley, the step cut can easily be done with a sawzall. Use a cutting lube of some sort (have a buddy spray it in spurts), even WD-40 works well. If you use a fresh roll of electrical tape, the radius will easily be cut with a sawzall, no problem.

[bubba72]

i hope that i'm not stealing this thread or something like that...

i saw ebfabmans cut he made and that would be doable but the radius cut on the steps would be tricky.

thanks for your help
joe

[glock35ipsc]

They can be done, I've done it, but even if you went with efabman's way without doing the radius'd corners, that would still give me warm fuzzies compared to the 45*.

Feel free to shoot me a PM if you have any other questions!

[Ackattack]

what is everyone doing for the bed?

I'm going to do this. Are you guys cutting the bed floor and fenders or what?